The present invention is related to a sensor assembly for determining selected properties of a gas. More particularly, the present invention relates to a wireless sensor assembly for measuring selected properties of a gas stream passing through a gas path housing.
The health and performance of structures such as turbine assemblies, blast furnaces, boilers, and the like can often be monitored by tracking a physical property, such as temperature, of a gas stream passing through such a structure. By monitoring levels and variations of such properties, structures such as those mentioned above may be operated at peak efficiency. In addition, such monitoring may serve as a diagnostic tool for identifying events within such structures that may lead to a degradation of performance.
For example, in a turbine engine, such as those widely used for power generation or aircraft propulsion, air enters the combustor section where it is combined with a fuel, such as natural gas or jet fuel, and burned continuously within a plurality of combustor cans. In most turbine designs, the combustor section typically includes about 14 combustors. The hot, high pressure air exiting the combustor section is then expanded before exiting the turbine engine through the exhaust section. As a result of the combustion of gases within the combustor cans, the gases passing through the exhaust section exhibit a distinctive temperature profile roughly corresponding to the annular distribution of combustor cans within the combustor section. Thus, an event that causes a combustor can to cease functioning will result in a corresponding change in the temperature profile.
Because the turbine engine typically contains about 14 combustor cans, multiple temperature probes are required to provide sufficient resolution to accurately monitor any changes in the temperature profile. The positioning of multiple temperature probes in the exhaust system is undesirable, due to the disruption of gas flow by such an array and the resulting loss of turbine efficiency. The use of multiple temperature probes is also impractical, due to the complex hard-wiring that such an array would require.
Thus, there is a need for a sensor system that is capable of monitoring and profiling the properties of a gas stream passing through a hot gas path housing, such as a turbine engine or assembly
A wireless sensor assembly for circumferential monitoring of gas stream properties comprises a drive system attachable to a hot gas path housing. A rake is movably coupled to the drive system for unrestricted circumferential movement. At least one RF sensor is disposed on the rake for generating a signal responsive to the gas stream properties. Circuitry is provided for remotely powering the at least one RF sensor and for remotely detecting the signal.